problem with mail server

hello,i got cpanel from cPanel Inc. and i got whmcs from WHMCS - The Complete Client Management, Billing & Support System ..the problem is that every time i answer a ticket in whmcs i have to go on whm and click on deliver message or everytime a new costumer register and need a order confirmation i have to go on whm and click deliver.... i got a cron command and i tryed in all the ways..but is not working..i need to make it work automatlly ..to send the mail automatlly ..not everytime i have to come to my pc to send the email registration or other things when it should work automatlly
..i set the time for mail queue to run at 5 minutes..5 hours passed and nothing and now when i try to send it mannualy i got this:
Message 1MPKOy-0004NX-1D is not frozen
delivering 1MPKOy-0004NX-1D
LOG: MAIN
== theworldismine_pc@yahoo.com R=lookuphost defer (-1): host lookup did not complete

Based on the message you posted at the end of you post, it looks like you are having some sort of DNS resolution problem on your server.

This could be caused by a misconfiguration of either your network settings, DNS server, or your email server configuration. It could also be caused by a firewall or other security application blocking port 53 which you need open incoming so other servers can resolve the domains you host and outbound so that your server is able to lookup the MX and IP information for destinations you try to contact such as by sending mail for example.

I would first check to make sure your DNS server is actually running:

Code:

# service named status

I would then check any firewall or port scanning monitors or other security applications you have installed and make sure you are not blocking port 53 on your server which must remain open in both directions.

If that does not lead you to the source of your issue then I would look at /etc/resolv.conf /etc/nameserverips and then finally start going through your "Tweak Settings" and "Exim Configuration" to see if you have something set incorrectly that might be effecting your mail server resolution.